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Revert "[PATCH] paravirt: Add startup infrastructure for paravirtualization"
[pv_ops_mirror.git] / drivers / s390 / char / zcore.c
blob89d439316a531cb3373a16b780de0fecc8cf7c78
1 /*
2 * zcore module to export memory content and register sets for creating system
3 * dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same
4 * dump format as s390 standalone dumps.
5 *
6 * For more information please refer to Documentation/s390/zfcpdump.txt
7 *
8 * Copyright IBM Corp. 2003,2007
9 * Author(s): Michael Holzheu
10 */
11
12 #include <linux/init.h>
13 #include <linux/miscdevice.h>
14 #include <linux/utsname.h>
15 #include <linux/debugfs.h>
16 #include <asm/ipl.h>
17 #include <asm/sclp.h>
18 #include <asm/setup.h>
19 #include <asm/sigp.h>
20 #include <asm/uaccess.h>
21 #include <asm/debug.h>
22 #include <asm/processor.h>
23 #include <asm/irqflags.h>
24
25 #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
26 #define MSG(x...) printk( KERN_ALERT x )
27 #define ERROR_MSG(x...) printk ( KERN_ALERT "DUMP: " x )
28
29 #define TO_USER 0
30 #define TO_KERNEL 1
31
32 enum arch_id {
33 ARCH_S390 = 0,
34 ARCH_S390X = 1,
35 };
36
37 /* dump system info */
38
39 struct sys_info {
40 enum arch_id arch;
41 unsigned long sa_base;
42 u32 sa_size;
43 int cpu_map[NR_CPUS];
44 unsigned long mem_size;
45 union save_area lc_mask;
46 };
47
48 static struct sys_info sys_info;
49 static struct debug_info *zcore_dbf;
50 static int hsa_available;
51 static struct dentry *zcore_dir;
52 static struct dentry *zcore_file;
53
54 /*
55 * Copy memory from HSA to kernel or user memory (not reentrant):
56 *
57 * @dest: Kernel or user buffer where memory should be copied to
58 * @src: Start address within HSA where data should be copied
59 * @count: Size of buffer, which should be copied
60 * @mode: Either TO_KERNEL or TO_USER
61 */
62 static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
63 {
64 int offs, blk_num;
65 static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
66
67 if (count == 0)
68 return 0;
69
70 /* copy first block */
71 offs = 0;
72 if ((src % PAGE_SIZE) != 0) {
73 blk_num = src / PAGE_SIZE + 2;
74 if (sclp_sdias_copy(buf, blk_num, 1)) {
75 TRACE("sclp_sdias_copy() failed\n");
76 return -EIO;
77 }
78 offs = min((PAGE_SIZE - (src % PAGE_SIZE)), count);
79 if (mode == TO_USER) {
80 if (copy_to_user((__force __user void*) dest,
81 buf + (src % PAGE_SIZE), offs))
82 return -EFAULT;
83 } else
84 memcpy(dest, buf + (src % PAGE_SIZE), offs);
85 }
86 if (offs == count)
87 goto out;
88
89 /* copy middle */
90 for (; (offs + PAGE_SIZE) <= count; offs += PAGE_SIZE) {
91 blk_num = (src + offs) / PAGE_SIZE + 2;
92 if (sclp_sdias_copy(buf, blk_num, 1)) {
93 TRACE("sclp_sdias_copy() failed\n");
94 return -EIO;
95 }
96 if (mode == TO_USER) {
97 if (copy_to_user((__force __user void*) dest + offs,
98 buf, PAGE_SIZE))
99 return -EFAULT;
100 } else
101 memcpy(dest + offs, buf, PAGE_SIZE);
102 }
103 if (offs == count)
104 goto out;
105
106 /* copy last block */
107 blk_num = (src + offs) / PAGE_SIZE + 2;
108 if (sclp_sdias_copy(buf, blk_num, 1)) {
109 TRACE("sclp_sdias_copy() failed\n");
110 return -EIO;
111 }
112 if (mode == TO_USER) {
113 if (copy_to_user((__force __user void*) dest + offs, buf,
114 PAGE_SIZE))
115 return -EFAULT;
116 } else
117 memcpy(dest + offs, buf, count - offs);
118 out:
119 return 0;
120 }
121
122 static int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
123 {
124 return memcpy_hsa((void __force *) dest, src, count, TO_USER);
125 }
126
127 static int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
128 {
129 return memcpy_hsa(dest, src, count, TO_KERNEL);
130 }
131
132 static int memcpy_real(void *dest, unsigned long src, size_t count)
133 {
134 unsigned long flags;
135 int rc = -EFAULT;
136 register unsigned long _dest asm("2") = (unsigned long) dest;
137 register unsigned long _len1 asm("3") = (unsigned long) count;
138 register unsigned long _src asm("4") = src;
139 register unsigned long _len2 asm("5") = (unsigned long) count;
140
141 if (count == 0)
142 return 0;
143 flags = __raw_local_irq_stnsm(0xf8); /* switch to real mode */
144 asm volatile (
145 "0: mvcle %1,%2,0x0\n"
146 "1: jo 0b\n"
147 " lhi %0,0x0\n"
148 "2:\n"
149 EX_TABLE(1b,2b)
150 : "+d" (rc)
151 : "d" (_dest), "d" (_src), "d" (_len1), "d" (_len2)
152 : "cc", "memory");
153 __raw_local_irq_ssm(flags);
154
155 return rc;
156 }
157
158 static int memcpy_real_user(__user void *dest, unsigned long src, size_t count)
159 {
160 static char buf[4096];
161 int offs = 0, size;
162
163 while (offs < count) {
164 size = min(sizeof(buf), count - offs);
165 if (memcpy_real(buf, src + offs, size))
166 return -EFAULT;
167 if (copy_to_user(dest + offs, buf, size))
168 return -EFAULT;
169 offs += size;
170 }
171 return 0;
172 }
173
174 #ifdef __s390x__
175 /*
176 * Convert s390x (64 bit) cpu info to s390 (32 bit) cpu info
177 */
178 static void __init s390x_to_s390_regs(union save_area *out, union save_area *in,
179 int cpu)
180 {
181 int i;
182
183 for (i = 0; i < 16; i++) {
184 out->s390.gp_regs[i] = in->s390x.gp_regs[i] & 0x00000000ffffffff;
185 out->s390.acc_regs[i] = in->s390x.acc_regs[i];
186 out->s390.ctrl_regs[i] =
187 in->s390x.ctrl_regs[i] & 0x00000000ffffffff;
188 }
189 /* locore for 31 bit has only space for fpregs 0,2,4,6 */
190 out->s390.fp_regs[0] = in->s390x.fp_regs[0];
191 out->s390.fp_regs[1] = in->s390x.fp_regs[2];
192 out->s390.fp_regs[2] = in->s390x.fp_regs[4];
193 out->s390.fp_regs[3] = in->s390x.fp_regs[6];
194 memcpy(&(out->s390.psw[0]), &(in->s390x.psw[0]), 4);
195 out->s390.psw[1] |= 0x8; /* set bit 12 */
196 memcpy(&(out->s390.psw[4]),&(in->s390x.psw[12]), 4);
197 out->s390.psw[4] |= 0x80; /* set (31bit) addressing bit */
198 out->s390.pref_reg = in->s390x.pref_reg;
199 out->s390.timer = in->s390x.timer;
200 out->s390.clk_cmp = in->s390x.clk_cmp;
201 }
202
203 static void __init s390x_to_s390_save_areas(void)
204 {
205 int i = 1;
206 static union save_area tmp;
207
208 while (zfcpdump_save_areas[i]) {
209 s390x_to_s390_regs(&tmp, zfcpdump_save_areas[i], i);
210 memcpy(zfcpdump_save_areas[i], &tmp, sizeof(tmp));
211 i++;
212 }
213 }
214
215 #endif /* __s390x__ */
216
217 static int __init init_cpu_info(enum arch_id arch)
218 {
219 union save_area *sa;
220
221 /* get info for boot cpu from lowcore, stored in the HSA */
222
223 sa = kmalloc(sizeof(*sa), GFP_KERNEL);
224 if (!sa) {
225 ERROR_MSG("kmalloc failed: %s: %i\n",__FUNCTION__, __LINE__);
226 return -ENOMEM;
227 }
228 if (memcpy_hsa_kernel(sa, sys_info.sa_base, sys_info.sa_size) < 0) {
229 ERROR_MSG("could not copy from HSA\n");
230 kfree(sa);
231 return -EIO;
232 }
233 zfcpdump_save_areas[0] = sa;
234
235 #ifdef __s390x__
236 /* convert s390x regs to s390, if we are dumping an s390 Linux */
237
238 if (arch == ARCH_S390)
239 s390x_to_s390_save_areas();
240 #endif
241
242 return 0;
243 }
244
245 static DEFINE_MUTEX(zcore_mutex);
246
247 #define DUMP_VERSION 0x3
248 #define DUMP_MAGIC 0xa8190173618f23fdULL
249 #define DUMP_ARCH_S390X 2
250 #define DUMP_ARCH_S390 1
251 #define HEADER_SIZE 4096
252
253 /* dump header dumped according to s390 crash dump format */
254
255 struct zcore_header {
256 u64 magic;
257 u32 version;
258 u32 header_size;
259 u32 dump_level;
260 u32 page_size;
261 u64 mem_size;
262 u64 mem_start;
263 u64 mem_end;
264 u32 num_pages;
265 u32 pad1;
266 u64 tod;
267 cpuid_t cpu_id;
268 u32 arch_id;
269 u32 build_arch;
270 char pad2[4016];
271 } __attribute__((packed,__aligned__(16)));
272
273 static struct zcore_header zcore_header = {
274 .magic = DUMP_MAGIC,
275 .version = DUMP_VERSION,
276 .header_size = 4096,
277 .dump_level = 0,
278 .page_size = PAGE_SIZE,
279 .mem_start = 0,
280 #ifdef __s390x__
281 .build_arch = DUMP_ARCH_S390X,
282 #else
283 .build_arch = DUMP_ARCH_S390,
284 #endif
285 };
286
287 /*
288 * Copy lowcore info to buffer. Use map in order to copy only register parts.
289 *
290 * @buf: User buffer
291 * @sa: Pointer to save area
292 * @sa_off: Offset in save area to copy
293 * @len: Number of bytes to copy
294 */
295 static int copy_lc(void __user *buf, void *sa, int sa_off, int len)
296 {
297 int i;
298 char *lc_mask = (char*)&sys_info.lc_mask;
299
300 for (i = 0; i < len; i++) {
301 if (!lc_mask[i + sa_off])
302 continue;
303 if (copy_to_user(buf + i, sa + sa_off + i, 1))
304 return -EFAULT;
305 }
306 return 0;
307 }
308
309 /*
310 * Copy lowcores info to memory, if necessary
311 *
312 * @buf: User buffer
313 * @addr: Start address of buffer in dump memory
314 * @count: Size of buffer
315 */
316 static int zcore_add_lc(char __user *buf, unsigned long start, size_t count)
317 {
318 unsigned long end;
319 int i = 0;
320
321 if (count == 0)
322 return 0;
323
324 end = start + count;
325 while (zfcpdump_save_areas[i]) {
326 unsigned long cp_start, cp_end; /* copy range */
327 unsigned long sa_start, sa_end; /* save area range */
328 unsigned long prefix;
329 unsigned long sa_off, len, buf_off;
330
331 if (sys_info.arch == ARCH_S390)
332 prefix = zfcpdump_save_areas[i]->s390.pref_reg;
333 else
334 prefix = zfcpdump_save_areas[i]->s390x.pref_reg;
335
336 sa_start = prefix + sys_info.sa_base;
337 sa_end = prefix + sys_info.sa_base + sys_info.sa_size;
338
339 if ((end < sa_start) || (start > sa_end))
340 goto next;
341 cp_start = max(start, sa_start);
342 cp_end = min(end, sa_end);
343
344 buf_off = cp_start - start;
345 sa_off = cp_start - sa_start;
346 len = cp_end - cp_start;
347
348 TRACE("copy_lc for: %lx\n", start);
349 if (copy_lc(buf + buf_off, zfcpdump_save_areas[i], sa_off, len))
350 return -EFAULT;
351 next:
352 i++;
353 }
354 return 0;
355 }
356
357 /*
358 * Read routine for zcore character device
359 * First 4K are dump header
360 * Next 32MB are HSA Memory
361 * Rest is read from absolute Memory
362 */
363 static ssize_t zcore_read(struct file *file, char __user *buf, size_t count,
364 loff_t *ppos)
365 {
366 unsigned long mem_start; /* Start address in memory */
367 size_t mem_offs; /* Offset in dump memory */
368 size_t hdr_count; /* Size of header part of output buffer */
369 size_t size;
370 int rc;
371
372 mutex_lock(&zcore_mutex);
373
374 if (*ppos > (sys_info.mem_size + HEADER_SIZE)) {
375 rc = -EINVAL;
376 goto fail;
377 }
378
379 count = min(count, (size_t) (sys_info.mem_size + HEADER_SIZE - *ppos));
380
381 /* Copy dump header */
382 if (*ppos < HEADER_SIZE) {
383 size = min(count, (size_t) (HEADER_SIZE - *ppos));
384 if (copy_to_user(buf, &zcore_header + *ppos, size)) {
385 rc = -EFAULT;
386 goto fail;
387 }
388 hdr_count = size;
389 mem_start = 0;
390 } else {
391 hdr_count = 0;
392 mem_start = *ppos - HEADER_SIZE;
393 }
394
395 mem_offs = 0;
396
397 /* Copy from HSA data */
398 if (*ppos < (ZFCPDUMP_HSA_SIZE + HEADER_SIZE)) {
399 size = min((count - hdr_count), (size_t) (ZFCPDUMP_HSA_SIZE
400 - mem_start));
401 rc = memcpy_hsa_user(buf + hdr_count, mem_start, size);
402 if (rc)
403 goto fail;
404
405 mem_offs += size;
406 }
407
408 /* Copy from real mem */
409 size = count - mem_offs - hdr_count;
410 rc = memcpy_real_user(buf + hdr_count + mem_offs, mem_start + mem_offs,
411 size);
412 if (rc)
413 goto fail;
414
415 /*
416 * Since s390 dump analysis tools like lcrash or crash
417 * expect register sets in the prefix pages of the cpus,
418 * we copy them into the read buffer, if necessary.
419 * buf + hdr_count: Start of memory part of output buffer
420 * mem_start: Start memory address to copy from
421 * count - hdr_count: Size of memory area to copy
422 */
423 if (zcore_add_lc(buf + hdr_count, mem_start, count - hdr_count)) {
424 rc = -EFAULT;
425 goto fail;
426 }
427 *ppos += count;
428 fail:
429 mutex_unlock(&zcore_mutex);
430 return (rc < 0) ? rc : count;
431 }
432
433 static int zcore_open(struct inode *inode, struct file *filp)
434 {
435 if (!hsa_available)
436 return -ENODATA;
437 else
438 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
439 }
440
441 static int zcore_release(struct inode *inode, struct file *filep)
442 {
443 diag308(DIAG308_REL_HSA, NULL);
444 hsa_available = 0;
445 return 0;
446 }
447
448 static loff_t zcore_lseek(struct file *file, loff_t offset, int orig)
449 {
450 loff_t rc;
451
452 mutex_lock(&zcore_mutex);
453 switch (orig) {
454 case 0:
455 file->f_pos = offset;
456 rc = file->f_pos;
457 break;
458 case 1:
459 file->f_pos += offset;
460 rc = file->f_pos;
461 break;
462 default:
463 rc = -EINVAL;
464 }
465 mutex_unlock(&zcore_mutex);
466 return rc;
467 }
468
469 static struct file_operations zcore_fops = {
470 .owner = THIS_MODULE,
471 .llseek = zcore_lseek,
472 .read = zcore_read,
473 .open = zcore_open,
474 .release = zcore_release,
475 };
476
477
478 static void __init set_s390_lc_mask(union save_area *map)
479 {
480 memset(&map->s390.ext_save, 0xff, sizeof(map->s390.ext_save));
481 memset(&map->s390.timer, 0xff, sizeof(map->s390.timer));
482 memset(&map->s390.clk_cmp, 0xff, sizeof(map->s390.clk_cmp));
483 memset(&map->s390.psw, 0xff, sizeof(map->s390.psw));
484 memset(&map->s390.pref_reg, 0xff, sizeof(map->s390.pref_reg));
485 memset(&map->s390.acc_regs, 0xff, sizeof(map->s390.acc_regs));
486 memset(&map->s390.fp_regs, 0xff, sizeof(map->s390.fp_regs));
487 memset(&map->s390.gp_regs, 0xff, sizeof(map->s390.gp_regs));
488 memset(&map->s390.ctrl_regs, 0xff, sizeof(map->s390.ctrl_regs));
489 }
490
491 static void __init set_s390x_lc_mask(union save_area *map)
492 {
493 memset(&map->s390x.fp_regs, 0xff, sizeof(map->s390x.fp_regs));
494 memset(&map->s390x.gp_regs, 0xff, sizeof(map->s390x.gp_regs));
495 memset(&map->s390x.psw, 0xff, sizeof(map->s390x.psw));
496 memset(&map->s390x.pref_reg, 0xff, sizeof(map->s390x.pref_reg));
497 memset(&map->s390x.fp_ctrl_reg, 0xff, sizeof(map->s390x.fp_ctrl_reg));
498 memset(&map->s390x.tod_reg, 0xff, sizeof(map->s390x.tod_reg));
499 memset(&map->s390x.timer, 0xff, sizeof(map->s390x.timer));
500 memset(&map->s390x.clk_cmp, 0xff, sizeof(map->s390x.clk_cmp));
501 memset(&map->s390x.acc_regs, 0xff, sizeof(map->s390x.acc_regs));
502 memset(&map->s390x.ctrl_regs, 0xff, sizeof(map->s390x.ctrl_regs));
503 }
504
505 /*
506 * Initialize dump globals for a given architecture
507 */
508 static int __init sys_info_init(enum arch_id arch)
509 {
510 switch (arch) {
511 case ARCH_S390X:
512 MSG("DETECTED 'S390X (64 bit) OS'\n");
513 sys_info.sa_base = SAVE_AREA_BASE_S390X;
514 sys_info.sa_size = sizeof(struct save_area_s390x);
515 set_s390x_lc_mask(&sys_info.lc_mask);
516 break;
517 case ARCH_S390:
518 MSG("DETECTED 'S390 (32 bit) OS'\n");
519 sys_info.sa_base = SAVE_AREA_BASE_S390;
520 sys_info.sa_size = sizeof(struct save_area_s390);
521 set_s390_lc_mask(&sys_info.lc_mask);
522 break;
523 default:
524 ERROR_MSG("unknown architecture 0x%x.\n",arch);
525 return -EINVAL;
526 }
527 sys_info.arch = arch;
528 if (init_cpu_info(arch)) {
529 ERROR_MSG("get cpu info failed\n");
530 return -ENOMEM;
531 }
532 sys_info.mem_size = real_memory_size;
533
534 return 0;
535 }
536
537 static int __init check_sdias(void)
538 {
539 int rc, act_hsa_size;
540
541 rc = sclp_sdias_blk_count();
542 if (rc < 0) {
543 ERROR_MSG("Could not determine HSA size\n");
544 return rc;
545 }
546 act_hsa_size = (rc - 1) * PAGE_SIZE;
547 if (act_hsa_size < ZFCPDUMP_HSA_SIZE) {
548 ERROR_MSG("HSA size too small: %i\n", act_hsa_size);
549 return -EINVAL;
550 }
551 return 0;
552 }
553
554 static void __init zcore_header_init(int arch, struct zcore_header *hdr)
555 {
556 if (arch == ARCH_S390X)
557 hdr->arch_id = DUMP_ARCH_S390X;
558 else
559 hdr->arch_id = DUMP_ARCH_S390;
560 hdr->mem_size = sys_info.mem_size;
561 hdr->mem_end = sys_info.mem_size;
562 hdr->num_pages = sys_info.mem_size / PAGE_SIZE;
563 hdr->tod = get_clock();
564 get_cpu_id(&hdr->cpu_id);
565 }
566
567 extern int sdias_init(void);
568
569 static int __init zcore_init(void)
570 {
571 unsigned char arch;
572 int rc;
573
574 if (ipl_info.type != IPL_TYPE_FCP_DUMP)
575 return -ENODATA;
576
577 zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
578 debug_register_view(zcore_dbf, &debug_sprintf_view);
579 debug_set_level(zcore_dbf, 6);
580
581 TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno);
582 TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
583 TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun);
584
585 rc = sdias_init();
586 if (rc)
587 goto fail;
588
589 rc = check_sdias();
590 if (rc) {
591 ERROR_MSG("Dump initialization failed\n");
592 goto fail;
593 }
594
595 rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
596 if (rc) {
597 ERROR_MSG("sdial memcpy for arch id failed\n");
598 goto fail;
599 }
600
601 #ifndef __s390x__
602 if (arch == ARCH_S390X) {
603 ERROR_MSG("32 bit dumper can't dump 64 bit system!\n");
604 rc = -EINVAL;
605 goto fail;
606 }
607 #endif
608
609 rc = sys_info_init(arch);
610 if (rc) {
611 ERROR_MSG("arch init failed\n");
612 goto fail;
613 }
614
615 zcore_header_init(arch, &zcore_header);
616
617 zcore_dir = debugfs_create_dir("zcore" , NULL);
618 if (!zcore_dir) {
619 rc = -ENOMEM;
620 goto fail;
621 }
622 zcore_file = debugfs_create_file("mem", S_IRUSR, zcore_dir, NULL,
623 &zcore_fops);
624 if (!zcore_file) {
625 debugfs_remove(zcore_dir);
626 rc = -ENOMEM;
627 goto fail;
628 }
629 hsa_available = 1;
630 return 0;
631
632 fail:
633 diag308(DIAG308_REL_HSA, NULL);
634 return rc;
635 }
636
637 extern void sdias_exit(void);
638
639 static void __exit zcore_exit(void)
640 {
641 debug_unregister(zcore_dbf);
642 sdias_exit();
643 diag308(DIAG308_REL_HSA, NULL);
644 }
645
646 MODULE_AUTHOR("Copyright IBM Corp. 2003,2007");
647 MODULE_DESCRIPTION("zcore module for zfcpdump support");
648 MODULE_LICENSE("GPL");
649
650 subsys_initcall(zcore_init);
651 module_exit(zcore_exit);
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